Television Pick-up Tubes Research Articles

143. CCD カメラと撮像管による画像変化(撮影技術-CCD カメラ)

143. CCD カメラと撮像管による画像変化(撮影技術-CCD カメラ)

143. CCD カメラと撮像管による画像変化(第 21 回秋季学術大会一般研究発表予稿)

143. CCD カメラと撮像管による画像変化(第 21 回秋季学術大会一般研究発表予稿)

Fly's eye: a counting camera for thermal neutrons

A two-dimensional position-sensing detector for thermal neutrons was developed to improve the data collection in single-crystal neutron diffraction experiments, small-angle diffraction patterns from fibers and membranes, inelastic scattering measurements using the multiangle reflection crystal technique, nuclear and magnetic diffraction topography, and diffraction and transmission measurements on samples in which phase changes are occurring. The detector is a unique tool for rapid inspection of crystal quality, isolating grains, and alignment of a number of small crystals so that they reflect together for intensity enhancement. Simple diffraction experiments were made to illustrate the range of application. The camera consists of a neutron phosphor screen, image intensifier, television pick-up tube, and digital storage. The stored information can be displayed in one-and two-dimensional formats and transferred to magnetic tape for computer analysis. The camera resolution is 0.13 mm full width at half maximum (fwhm) horizontal and 1.0 mm vertical, which corresponds to more than 80000 detector elements over the useful area of the nominal 150 mm diameter phosphor screen. The counting rate per detector element is 60 regularly occurring events per second. The counting efficiency is ~15% for a 0–5 mm thick phosphor.

General physics and electronics

The multiplication by secondary emission of a stream of electrons has been developed to a very high degree, and the electron gains of 108 or 109 have been made readily achievable. Thus, the detection—either optically or electronically—of single-photon incident on a photocathode has been rendered possible. This fact suggests the possibility of constructing a tube in which the photoelectrons from an array of image points on the photocathode are separately multiplied but retained as a coherent electron image after multiplication, to give an image of much higher electron density. The electrons may then be accelerated onto a phosphor screen, or other detecting element, which might, for example, be the charge storage target of a television pick-up tube. The construction of a system of channeled secondary emission dynodes is feasible due to the work done in the past. This chapter experimentally investigates three types of electrode structures—that is, a “venetian blind” type of photomultiplier, a symmetrical cylindrical structure, and an asymmetrical cylindrical structure. Even if high definition intensified images may never be achieved by such devices, the very large multiplication factors that are to be expected would enable single primary photoelectrons to be detected visually or photographically with relatively uncomplicated apparatus. This would almost certainly render it a most powerful tool in many fields of scientific observation.

243. Photoconductive television pick-up tubes: M Jedlicka,Slabopr Obzor, 33 (1), Jan 1972, 21–28 ( in Czech)

243. Photoconductive television pick-up tubes: M Jedlicka,Slabopr Obzor, 33 (1), Jan 1972, 21–28 ( in Czech)

156. Pre-commutation noise in television pick-up tubes: V L Lentsman,Radiotekh Elektron, 16 (10), 1971, 1927–1935 ( in Russian)

156. Pre-commutation noise in television pick-up tubes: V L Lentsman,Radiotekh Elektron, 16 (10), 1971, 1927–1935 ( in Russian)

Industrial Application of the Semiconductor Properties of Dyes

AbstractEffects of industrial interest have been detected in investigations on the dark conductivity and photoconductivity of dyes. For example, it was found that organic dyes can be used in the same way as inorganic photoconductors in vidicon television pickup tubes for the reproduction of images. Among other things, pointers were obtained to the formation of rectifying and photoelectrically sensitive pn junctions, to relatively high thermoelectromotive forces of doped and polymeric dyes, to the possibility of use in reprography, and to a high catalytic activity connected with the conductivity, which is already being utilized in fuel cells.

Radiation Sensitivity of Silicon Imaging Sensors on Missions to the Outer Planets

An investigation of radiation damage mechanisms and the magnitude of their effects on the operating characteristics of imaging sensors utilizing a mosaic array of silicon diodes in a television pickup tube is reported. The effects produced by bombardment of bare-silicon-diode arrays or vidicon tubes with 85kV x-rays, Cobalt 60 gamma rays, 1 MeV and 11 MeV electrons, 3 MeV and 142 MeV protons, and reactor neutrons are presented. Results show that the dark (reverse bias) current of a diode array increases less than a factor of 2 if the fluence level is less than 104 rads of gamma radiation or 4 ×1011 1 MeV electrons/cm2. For these same dose levels, the quantum efficiency increases rather than decreases. Continued bombardment in excess of these fluences decreases the quantum efficiency and increases the dark current. Electrons of 11 MeV were more damaging than 1 MeV electrons by a factor of 10 to 20 while protons of 3 MeV more effectively produced dark current increases and quantum efficiency degradation in silicon diode arrays than 1 MeV electrons by a factor of 105 in fluence. Protons of 142 MeV were less effective than 3 MeV protons in producing the same effects by a factor of 102 in fluence. Measurements of these degradation effects at 217 K indicated that the dark current is reduced by a factor of 200 to 500 relative to room-temperature values.

Recent Progress in Television Pick-up Tubes

Recent Progress in Television Pick-up Tubes

On the beamless scanning principle and scanistors

The beamless scanning principle was proposed in 1934 by the author. A television pick-up tube using this principle played a significant role in the history of television in the U.S.S.R. It is pointed out that the operation of some recent solid-state devices is based on this same principle.

Integrating Video Microdensitometer

A sensitive integrating microdensitometer for evaluation of diffraction films is reported. The instrument is simple in construction and requires no critical alignment. Contrary to general designs the scanning is done with the receiver by a Vidicon television pickup tube serving both as light sensitive element and scanning device. Circuits for processing the video signal are described.

撮像管の解像度と階調

テレビジョンの画質は,解像度,階調,雑音などにより決定される.ここでは,イメージオルシコンおよびビジコンの解像度と階調につき,最近までに各国で行なわれた研究につき概説する.

A Simplified Method of Conversion of Standard Intermittent Motion-Picture Projectors for Use with Television Pickup Tubes

A 35mm Simplex projection head was converted for use as a television projector with the 3:2 field-sequence method of utilizing film taken at the rate of 24 frames/sec for the 30-frames/sec television standard. A 35% application time is obtainable with a 5-in.-diameter shutter blade running at 3600 rpm. The entire mechanism, including the feed and holdback sprockets, shutter and intermittent Geneva, is driven from a single 1800-rpm synchronous motor. A timing belt drive is used for the intermittent mechanism. An eccentric toothed idler pulley of twice the diameter of the Geneva drive pulley is interposed between the motor and the Geneva drive to produce the required advance and retard modification of the rotary motion. The timing and change of acceleration are illustrated by curves. This method of conversion offers the advantages of simplicity and economy. Very little added noise or acceleration loading is produced and long operating life may be expected.

Television pick-up tubes for x-ray screen intensification.

This paper is primarily concerned with the application of television systems to X-ray screen intensification, in particular to systems built around the image-orthicon type of camera tube. One object of screen intensification in fluoroscopy is to present to the physician a display which is so much brighter than the normal fluoroscopic image that he does not need to become dark-adapted before making an examination. It takes 30 minutes or more for the eye to attain its maximum sensitivity after entering the darkroom and during this time the gain in sensitivity may be as much as 10,000 times. This gives an indication of the degree of image brightening required to compensate for dark adaptation. A further object is to obtain maximum information from the fluoroscope without exceeding the permissible X-ray dosage; indeed, it is desirable to lower the dosage if possible in order to reduce the probability of later harmful effects to the patient. The dark-adapted eye can resolve little detail, due partly to the physical structure of the retina and partly to the low number of photons usefully collected. The eye has very low resolution at the light levels experienced in fluoroscopy. By bringing the light level of the image into the photopic range of vision, screen intensification enables the eye to utilise all the information available at the fluoroscopic screen but, of course, no more.

Beam temperature, discharge lag and target biasing in some television pick-up tubes

Discharge lag in pick-up tubes, particularly of modern cathode-potential-stabilized type, and its relation to the acceptance of the electron beam by the target are analysed. Measurements of beam acceptance as a function of target potential reveal effective beam temperatures substantially equal to cathode temperature at low beam currents, but higher and multi-valued at high currents. These temperatures set a limit to the possible reduction of lag without target biasing; this limiting lag, referred to as Maxwellian lag, is calculated and presented graphically. Direct measurements of lag are compared with the limiting values. Target biasing, the application of a small positive potential to the target face, reduces this limitation. Results of electron-optical measurements, throwing some light on the anomalous beam temperatures, are presented.

Beam temperature, discharge lag and target biasing in some television pick-up tubes

Discharge lag in pick-up tubes, particularly of modern cathode-potential-stabilized type, and its relation to the acceptance of the electron beam by the target are analysed. Measurements of beam acceptance as a function of target potential reveal effective beam temperatures substantially equal to cathode temperature at low beam currents, but higher and multi-valued at high currents. These temperatures set a limit to the possible reduction of lag without target biasing; this limiting lag, referred to as Maxwellian lag, is calculated and presented graphically. Direct measurements of lag are compared with the limiting values. Target biasing, the application of a small positive potential to the target face, reduces this limitation. Results of electron-optical measurements, throwing some light on the anomalous beam temperatures, are presented.

On the error balancing of an optical system in combination with its receiver.

The problem of how the aberration of a lens should be balanced is studied in order to get the best result in combination with its receiver (photographic emulsion, television pick-up tube, etc.).The intensity distribution of light in the line image formed by the lens is assumed to be expressed approximately by the sum of two error functions corresponding to the image core and halo, respectively, and the diffusing characteristics of the light receiver are represented by a third error function. A formula is deduced which expresses the resultant response of the total system (lens plus receiver) with parameters used in the three error functions described above. As a measure of the over-all image quality of the total system the maximum value in the resultant response (S.D.)—the generalized Strehl definition—is chosen.This method is applied to the error balancing of a lens having primary and secondary spherical aberration, the intensity distribution being obtained by spot diagrams. As a result, the over-corrected type is better when the receiver has a small degree of diffusion, and the under-corrected type is preferred when it has a large one.

Television pick-up tubes. Part II: Design, operation and characteristics

In this, the second part of Professor McGee's review, he describes the essential features of five well-known pick-up tubes. Each of these represents a small group of tubes, and illustrates a stage in development, although every tube described is still in use to-day. The first part of the review appeared in the July issue, page 404.

Television pick-up tubes. Part I: Physical principles

Television pick-up tubes. Part I: Physical principles

X-Ray Noise Observation Using a Photoconductive Pickup Tube

A television pickup tube arrangement using a Vidicon for the direct recording of x-ray images is described. The transmitted x-ray picture shows noise characteristics that are clearly those of the absorbed x-ray photons. The internal conversion gain (number of carriers generated per absorbed x-ray photon) is estimated by two independent methods, one of which is based on a measurement of x-ray noise. Both methods give a gain of about 500 for a 100 kv x-ray photon. The agreement between the two methods is evidence for the validity of the simple electron-multiplier model for the noise current in the photoconductive selenium target. The appearance of x-ray noise means that all the information contained in the absorbed fraction of the x-ray beam is being transmitted. Thirty pictures per second are transmitted when irradiating the Vidicon with a 5 ma, 100 kv x-ray beam at a distance of two feet. Wires of one mil diameter were clearly observable.